Tobacco moistening



Sept. 13, 1966 F. B. DOYLE TOBACCO MOISTENING Filed Feb. 6, 1964Inventor FRANK B. DOYLE 85/ y rlgz, m't'fi fH-ko (11.215 6 WATER TEMP.IH PAN \08 0F F\G.|.

United States Patent 3,272,207 TOBACCQ MOISTENING Frank B. Doyle, R0.Box 237, Raymond, Ill. Filed Feb. 6, 1964, Ser. No. 343,090 7 Claims.(Cl. 131-133) The present invention relates to an improved process andapparatus for conditioning organic products in bulk and, moreparticularly, it relates to a process and appa ratus for conditioningtobacco.

Tobacco generally is stored for lengthy periods between the time that itis harvested from the fields and the time that it is used. When tobaccois stored for such periods, moisture is dissipated from the leaves andthe product becomes dry and brittle. It, therefore, is necessary tocondition the product prior to use. In moistening bulk products, such astobacco, the material generally is placed in a hermetically sealedchamber from which air is drawn. Steam then is introduced to thechamber, the chamber again evacuated and steamed a second time toincrease the probability of even distribution of moisture throughout thebody of tobacco. The above steps may, of course, be repeated until asatisfactory product is realized. It should be noted, however, thateconomical processing must be realized in order to provide a productthat will be competitive and to that extent moistening in optimum timeis desired.

The method and apparatus set forth herein include means set forth in myPatents 2,832,353 and 2,997,046, relating to equipment for moisteningmaterials in bulk.

A frequent problem encountered in the conditioning or moistening oftobacco products in bulk is that cold spots occur Within the body oftobacco. These cold spots are defined by areas of tobacco that have notbeen moistened and warmed during the steaming portion of theconditioning cycle. One cause of such cold spots is that all of theresidual air or non-condensible gases may not be removed from thehogshead of tobacco and pockets form to block movement of the steamfront uniformly over the entire tobacco surface. Repeated cycling, i.e.evacuation and steaming, will improve the uniformity of the treatedtobacco product, but frequently cold spots will still occur.

The apparatus and method as set forth here-in do not introduce steamdirectly into the chamber. The steam, instead, is passed into thecondenser, through the first stage ejector, and then into theconditioning chamber. By this method steam of the proper quality issupplied to the chamber Without the need of supplementary moisteningdevices as required on conditioning apparatus in conventionalconditioning processes. It has been found that the condenser and ejectorabsorb a sufficient quantity of heat from the steam to render itsuitable for conditioning the tobacco. It is important, however, thatthe air-vapor mixture in the condenser be controlled carefully duringevacuation of the chamber and of the condenser during initial evacuationthereof to assure that non-condensible gases are exhausted to atmosphereand do not remain in the chamber or condenser for introduction to thetobacco during the steaming portion of the conditioning cycle.

In the vacuum process for conditioning tobacco, or other organicmaterial to add moisture thereto, it first is necessary to evacuate theconditioning chamber to a suffici'ently low absolute pressure so thatmoisture will be evaporated from the material. Vapor continues to bedischarged from the material due to the fact that water molecules arecontinuously being withdrawn from the chamber are-a and it is thenatural characteristic of any fluid to reach equilibrium condition inits local area. To this extent evaporation will continue and will serveto remove or scrub out the residual air or non-condensible gases fromthe inter-cellular spaces of the hygroscopic materials so that whenwater vapor is admitted to the conditioning chamber during the steamingportion of the conditioning cycle, the vapor Will readily penetrate allof the fibers of the material, condense upon the relatively coolersurfaces and add the desired moisture to the material.

It should be observed that when the outside temperature at the tobaccoconditioning installation is relatively low the initial evacuationperiod required to evacuate the conditioning chamber and the condensermust be lengthened relative to the evacuation period during elevatedambient temperature conditions to reduce the absolute pressure in theconditioning chamber to the point where the vapor in the tobacco, orother material, begins to be expelled from the material. During thesecolder conditions, the cooling water supplied to the condenser of thesystem is relatively cold and if the system, for example, is adjusted toadmit the larger amount of cooling water required during elevatedthermal conditions then the condenser Will be at too low a temperaturefor optimum processing. The increased evacuation time during initialcycling with low ambient temperate conditions is essential to assureremoval of air from both of the chamber and the condenser space.Further, the cold condenser Water introduced during the low outsidetemperature conditions introduces little water vapor to the condenserspace.

The present invention is directed to the provision of an improvedprocess and apparatus wherein the non-condensible gases are removed fromthe system during conditioning. The process and apparatus of the presentinvention contemplate the use of means to control the airvapor mixtureWithin the condenser, to assure proper preparation of the condenser forthe steaming portion of the cycle and thereby to provide a system thatwill not result in reintroduction of non-condensible gases to theconditioning chamber during the steaming portion of the conditioningcycle. The invention is specifically directed to the provision of meansto control the absolute pressure (or temperature, which is a function ofthe pressure) in the condenser. It should be observed that if thenon-condensible gases are not removed from the conditioning chamberduring initial evacuation, or if non-condensible gases are introducedduring steaming, said noncondensibles will enter the body of materialbeing conditioned along with the steam and will define a block toprevent the entry of steamto the gas occupied portion of the tobacco ormaterial with the result that a cold spot (unconditioned area) will beformed due to failure of the steam to reach the area to moisten and Warmthe body of tobacco. These cold spots are highly objectionable in aconditioned product and may result in partial product loss uponsubsequent processing of the conditioned tobacco, or other material.

It, therefore, is a general object of the present invention to providean improved method and apparatus for conditioning tobacco.

Another object of the present invention resides in the provision of animproved method for conditioning tobacco wherein steam for conditioningsaid tobacco is introduced to the conditioning chamber through acondenser.

A further object of the present invention resides in the provision of animproved method for condtioning tobacco that eliminates cold spots inthe conditioned tobacco regardless of ambient conditions under Which themethod is performed.

An additional object of the present invention resides in the provisionof an improved tobacco moistening apparatus having means to control thecharacter of the air-vapor mixture within the condenser during theconditioning cycle.

A further object of the present invention resides in the provision of animproved apparatus for moistening tobacco having means continuously tocontrol the vapor condition within the condenser above the dead endlevel of the condenser ejector to assure discharge of non-condensiblegases to atmosphere.

Another object of the present invention resides in the provision of animproved method for conditioning tobacco wherein the body of tobacco isuniformly moistened and warmed by steam of proper character andcondition, the steam passing through the condenser and first stageejector path prior to injection into the conditioning chamber.

A further object of the present invention resides in the provision of animproved method for conditioning tobacco that is economical to use, thatprovides uniform conditioning of tobacco regardless of ambientconditions in which the process is conducted and that is readily adaptedfor use with present conditioning equipment of the type set forthherein.

An additional object of the present invention resides in the provisionof an improved apparatus for conditioning tobacco that is easy toinstall in present conditioning apparatus, that is economical to installand use, that is durable in continued use, that is adapted to closeconditioning control during processing, that will provide a uniformconditioned product in use, that will assure uniform conditioning of thetobacco free from cold spots and in optimum processing times.

The novel features which are believed to be characteristic of myinvention are set forth with particularity in the appended claims. Theinvention itself, however, together with further objects and advantagesthereof, will best be understood by reference to the followingdescription taken in conjunction with the accompanying drawings, inwhich:

FIGURE 1 is an elevation view, with parts broken away, of tobaccomoistening means for conditioning said tobacco in the manner set forthherein; and

FIGURE 2 is a graphic illustration of the control and sequencing of theconditioning method.

As seen in FIGURE 1, tobacco moistening equipment of the type that maybe employed in carrying out conditioning of the tobacco product inaccord with the present invention includes a hermetically sealedchamber, illustrated generally at 10. The chamber may be adapted toreceive one or more hogsheads of tobacco, indicated at 12, dependingupon the requirements of the user. The chamber 10 includes removabledoors 14 and 16 at either end thereof securely fastened to the body ofsaid chamber during the conditioning process, said doors defining meansfor insertion and removal of the tobacco. Chamber 10 includes a ceiling18 and floor 20. The ceiling or top 18 is provided with an opening 22through which the chamber can be evacuated and through which steam isintroduced.

A conduit 24 is connected to the opening 22 of chamber 10 in air-tightrelation therewith and extends continuously between the chamber 10 andthe low pressure side 30 of the evacuating means 32 (described in detailhereinbelow) for the conditioning chamber. A conduit 26, communicatingwith the atmosphere, is connected to the pipe 24 and chamber 10. Thepipe 26 is provided with a valve 28 which, when opened, serves to breakthe vacuum in chamber 10 and to connect chamber 10 to atmosphere.

As noted above, the low pressure side 30 f the chamber evacuator orsteam ejector 32 is connected to the chamber through conduit 24. Thefirst stage or chamber ejector 32 preferably is of the type disclosed inmy Patent 2,997,046, wherein the throat area 34 of said ejector is atleast .05 square inch per cubic foot of volume of the conditioningchamber. Other dimensions and variations are set forth in detail in saidpatent. The discharge side 36 of the evacuator 32 is connected to thecondenser 38.

A steam supply source 40 is provided for the improved process andapparatus of the present invention. Thelow pressure side 30 of evacuatoror steam ejector 32 is connected to the steam source 40 through flowcontrol valve 42 and conduit 44. When the valve 42 is opened steam isintroduced to the evacuator 32, passes through the throat 34 and throughthe discharge 36 to condenser 38. When steam is introduced through thenozzle 46 of the evacuator 32, a lower pressure area is established, asindicated generally at 47, to draw non-condensible gases from theconditioning chamber 10 thereby lowering the pressure in said chamber.Preferably evacuation of the chamber 10 is continued until vaporizationof moisture occurs from the tobacco product to be conditioned. Thisvaporization will assist in removal of non-condensible gases from thebody of tobacco and will help to prepare the product for optimumconditioning during the steaming portion of the cycle.

The second stage, condenser ejector or evacuator 48 is defined by a lowpressure side 50, a reduced throat area 52 and a discharge side 54. Thelow pressure side 50 of ejector 48 is connected to the condenser 38through the conduit 56. The discharge side 54 of ejector 48 exhausts toatmosphere through valve 58. The valve 58 is operable to open or closedposition by an air cylinder valve operator 60.

The low pressure side of ejector 58 is connected through the valve 62and conduit 64 to the steam source 40. When the valve 62 is opened steamis introduced into the low pressure side 50 of the ejector 48 throughthe nozzle 51 creating a lowered pressure in area 53 to evacuate thecondenser 38 through said ejector. During evacuation of the chamber 10and condenser 38 the valve 58 is in open position to permit discharge ofsteam and non-condensible gases to atmosphere.

The condenser 38 is connected to the cooling water supply 66 throughconduit 68, safety shut-off valve 70 and automatic fiow control valve72. The cooling water from supply 66 flows into the condenser todistributor plate 74 to provide water dispersion in a manner mosteffective to assure full interchange of the vapors in the condenser withthe cooled water. The condensed fluids collect at the bottom of thecondenser 38. A fluid pump 76, driven by an electric motor 78, pumps thecondensed fluids back to the cooling tower 66 through conduit forrecirculation after cooling in the tower 66. Pump 82 may be employed toaid the pumping action. The pump 82 is driven by electric motor 84. Whenmotor 78 is not operating during the cycle the water circulates throughconduit 68, conduit 86, flow controller 88, pump 82 and conduit 80 toreduce the temperature of the water in the cooling tower 66. A checkvalve 77 is provided in conduit 80 to prevent back flow of fluid towardpump 76.

Steam may be introduced to the condenser by closing valve 58 causing aback flow into the condenser from supply 40. The steam is introduced tothe condenser prior to introduction to the conditioning chamber 10 formoistening and warming of the tobacco. In view of the nature of thisprocessing wherein steam is introduced to the chamber 10 through thecondenser 38 it is essential that the non-condensible gases be removedfrom the condenser 38 so that they will not be reintroduced to thechamber 10 and thereby to the tobacco 12 in the chamber during thesteaming portion of the conditioning cycle. The most important objectduring conditioning, of course, is to introduce only water vapor to thechamber during steaming so that there will be no cold spots and therebythe tobacco may be uniformly conditioned in optimum conditioning time.

The condenser 38 is provided with a transducer 96 adapted to measure thecondition of a variable inside the condenser. The transducer may be inthe form of a pneumatic or electric sensing device of the type known inthe control art for measuring the condition of a function and convertingthe measurement to a pneumatic or electric signal proportional to themeasured level of said condition. The signal proportional to themeasured level of the condition is fed through means, indicated at 98,to the control element 100 of the flow control valve 72. The controlelement 100 is moved in response to the signal to a position which is afunction of the measured level of the variable condition Within thecondenser to vary the rate of flow of cooling water to the condenser byopening or closing the closure element of valve 72 in accord with thesignal feedback from the transducer 96.

The transducer 96, in this present invention, preferably is an absolutepressure controller and is adapted to measure the absolute pressure inthe condenser 38. The sig nal fed to the control valve 72 is directed tocontrol the rate of cooling Water from supply 66 to keep the absolutepressure in the condenser at a level above the dead end level of thesecond stage ejector 48 so that the non-condensible gas Will be removedfrom the condenser and exhausted to atmosphere. The transducer 96 isadjusted to respond to the need of the predetermined absolute pressurelevel in the condenser to control the position of the valve 72 andthereby the rate of flow of water to the condenser 38 during evacuationof the apparatus prior to steaming. It should be observed that thetransducer 96 may be a thermally responsive device adapted to measurethe sensible heat in the space 39 and to control the flow of coolingwater in accord with the measured temperature level. Temperature, ofcourse, is a function of the absolute pressure. A device of this typemay be acceptable due to .low initial cost, acceptable control response,and durability in use. The controller 100 may serve to move the valveclosure member of valve 72 to full open or full closed position inaccord with the magnitude or character of the signal from transducer 96.Thus, in one position flow of cooling water to the condenser 38 may beterminated.

Operating control ofthe moistening process and equipment may be achievedwith an automatic controller 102. The controller 102 includes a timer104, which timer may be an electric motor having a geared shaft. Thevalves 28, 42, 62, 70 and 58 may be automatically operated valvesactuated by compressed air controlled by pilot valves. The pilot valves28a, 42a, 62a, 70a and 60a are installed in the automatic controller 102and may be operated by cams carried on the shaft of the timer 104. Pilotvalve 70a is provided only to open valve 70 to permit introduction ofwater to the condenser space 39. The rate of flow of Water throughconduit 68 to the plate 74 will be governed by the flow control valve 72in the manner set forth hereinbelow. Timer 104 also operates acam-operated switch 78a which controls the energization of electricmotor 78 which drives the water pump 76. The automatic controller 102has a temperature controller 106 which is connected to a bulb 10611 inwater in a pan 108 on the top of the chamber below the opening 22. Thetemperature controller operates to turn on the timer 104 after apredetermined temperature has been reached. The timer has a cam Which,after a predetermined time, resets the temperature controller 106 sothat it will energize the timer 104 at a new predetermined temperature.Such a temperature controller is described in Taylor InstrumentCompanies Bulletin 98,159 of April, 1953.

Operation of the conditioning cycles with the apparatus herein describedis commenced by placing the hogsheads of tobacco 12 within the chamber10 and sealing the doors 14 and 16 at either end to provide an air-tightchamber area. The temperature of the water in the pan 108 will be about120 degrees Fahrenheit from the previous conditioning cycle. At thispoint in the cycle all of the automatically operable valves are closedand the pump motor 78 is de-energized.

In the process of the present invention the controller 102 is programmedto permit the second stage ejector 48 to begin the cycle and to operatefor a predetermined period to evacuate the condenser space 39. Thesecond stage ejector 48 is rendered operative by opening of valve 62 bypilot valve 62a. This will permit the introduction of steam to the lowpressure side 50 of the ejector 48. Simultaneously with the opening ofvalve 62 the pilot valve 60a operates to open the valve 58 through theair cylinder operator 60 to permit discharge of the steam to atmosphere.In one particular installation and with a second stage ejector with avarying capacity of zero pounds per hour at 1.6 inches of mercuryabsolute pressure to 6,600 pounds per hour at 30 inches of mercuryabsolute pressure I found that after about seven minutes of operationthe absolute pressure in the condenser space was reduced to about 1.6inches of mercury, the dead end point of the ejector employed. From thetable of Properties of Saturated Steam-Temperature it will be found that1.6 inches of mercury absolute pressure corresponds to about 94 F.

Thus, at T the second stage ejector is rendered operative and iseffective to begin evacuation of the condenser space 39. At time T andduring continued evacuation of the space 39, the absolute pressure inthe chamber 10 is reduced to a point where the water therein begins tovaporize taking away heat and lowering the temperature of the water inpan 108. At time T the valves 42 and 70 are opened by the controller 104and the pump motor 78 is energized to begin pumping action by the pump76. Opening of valve 70 permits the circulation of water through thecondenser 38 and opening of valve 42 begins the operation of the firststage ejector. When the first stage ejector 32 is operating the chamber10 is quickly evacuated to remove vapor and non-condensibles therefrom.The vapor is condensed and in the condenser space 39 while thenon-condensibles are discharged to atmosphere through the second stageejector 48.

During operation of the first stage ejector, the vapor passing from thedischarge side 36 thereof into condenser space 39 will, of course, be atrelatively high temperatures. In our specific example, noted above, ifthe vapors in the space 39 are maintained below 94 F. the absolutepressure in the condenser 38 will remain at about 1.6 inches of mercury.If, however, the vapors in condenser space 39 rise to, for example, F.,then the absolute pressure will rise to about 1.933 inches of mercury.Sufficient Water will vaporize in this condition to satisfy the capacityof the second stage ejector. The first stage ejector 32 remainsoperative until the pressure in the chamber 10 is reduced to the deadend point of said ejector.

It has 'been considered to be good operating practice, when conditioningtobacco with equipment of the type noted herein, to provide condensercooling water at as low a temperature as feasible. The theory of thisoperating practice is that with colder condenser water the first stageejector will evacuate the chamber 10 to a slightly lower absolutepressure than it would if the process were operated at designconditions. I have discovered the surprising fact that careful controlof the temperature of the condenser water will eliminate the cold spots(unconditioned areas) in the tobacco being conditioned to assure auniformly conditioned product regardless Otf the ambient conditionsunder which the process is carried out. Such conditioning control isdifficult to achieve with present operating methods and equipment.

I have noted that the cold spots in the tobacco tend to occur when theprocess is carried out under conditions wherein the body of tobacco maybe introduced to the chamber 10 while relatively cool (e.g. about 40F.)as occurs during winter in the higher latitudes-and wherein thecooling water employed in the process (or the waste water if a wasteWater conditioning process is being employed) also is relatively cool.

If, for example, the body of tobacco is taken directly from a warehousewithout prior warming and introduced to the chamber at about 40 F. thenit is apparent that the chamber temperature must be lowered below 40 F.in order to flash the moisture from the center of the body of tobacco toflush out the non-condensibles trapped therein. It should be noted thatthe temperature of operation of the process is a function of theabsolute pressure in the system and to that extent as a measuredcondition, may be interchangeable therewith in function for operation ofthe process in the manner desired. If the condenser water supply also isat about 40 F. the second stage ejector will dead end at about 1.6inches of mercury absolute. If the water flow is not carefullycontrolled or is adjusted to permit large temperature rises in accordwith design of the equipment (for example, if the condenser is regulatedfor operation under ambient conditions higher than the relatively coolconditions described) the water flow will be sufficient to permitcontinued cooling of the space 39. Under such operating conditions thetemperature in space 39 may rise to the design maximum, 15 F. forexample, resulting in a temperature of 55 F. (40 F. and 15 F.). From thetables of Properties of Saturated Air-Vapor Mixtures it can be seen thatat 1.6 inches of mercury absolute pressure at 55 F. the percent of dryair, by weight, in a mixture of air saturated with water vapor is 82%.It can readily be seen that an appreciable amount of air will remain inthe condenser space 39 under such conditions.

With my apparatus and process the quantity of cooling water to thecondenser space 39 will be reduced in accord with the control functionof the transducer 96 acting upon the valve 72 so that the operatingsteam from the discharge of the first stage ejector plus the vapor fromthe tobacco will elevate the sensible temperature in space 39 (forexample, to 100 F.). The corresponding absolute pressure noted in thetables will be 1.933 inches mercury. This same table will indicate thatzero percent of air is present at this condition. The second stageejector can effectively remove the non-condensibles from the space 39since at this absolute pressure the second stage ejector has anappreciable air handling capacity and would scrub the air out of thespace 39 to a point where the ejector was being satisfied by the vaporbeing boiled off of the condenser water.

At time T the second stage ejector is shut down by closing valves 58 and62, the first stage ejector is shut down by closing valve 42 and thesupply of cooling water is terminated by closing valve 70. Valve 58 isclosed and steam is introduced to the condenser space 39 from the steamsupply 40. The steam then flows from the condenser space 39 through thefirst stage ejector 32, through conduit 24 and into the conditioningchamber 10.

When the steam is introduced directly into a chamber from a source it isin the super-heated stage because of the expansion of the steam and thepressure reduction. In this condition moisture must be added from anexternal source of water to produce the necessary moistening of theproduct. However, in the present apparatus and with the process hereindescribed, the supplementary addition of moisture is not required. Asthe steam passes through the condenser space 39 and the ejector 32,sufiicient heat is absorbed by these structures before the steam isintroduced into the chamber to bring the steam to a saturated state tomoisten the product.

The temperature within the chamber 10 rises when the steam is introduceduntil it reaches a predetermined value as established by the temperaturecontrol 106 which value may, for example, be 150 F. When thistemperature is reached at T the timer 104 is actuated by .thetemperature controller 106 in response to said temperature level.

' At time T the valve 58 is opened and re-evacuation of the chamber isresumed. Re-evacuation and steaming are repeated as indicated at Tthrough T to assure uniform conditioning of the tobacco within thechamber 10. At time T the steam fiow to chamber 10 through the condenser38 is again terminated and the second stage ejector 48 is renderedoperative to resume evacuation by said ejector. At time T valve 70 isopened by the controller 102 to begin the flow of water to the condenserspace. Before the time T the timer motor actuates the temperaturecontroller 106 to lower the predetermined temperature at which thecontroller 106 energizes the timer 104. This new predeterminedtemperature may be, for example, F. At time T the fiow of water to thecondenser is again terminated, the.

ejector 48 is rendered inoperative, and the valve 28 is opened to breakthe vacuum in said chamber at time T It should be observed that anisolating valve may be employed in the place of the vacuum breaker valve28 Without altering the operation of the process disclosed herein.

While a specific embodiment of the present invention is shown anddescribed it will, of course, be understood that process modificationsand alternative constructions may be used without departing from thetrue spirit and scope of the invention. It isintended by the appendedclaims to cover all such process modifications and alternativeconstructions as fall within their true spirit and scope.

What I claim as new and desire to secure by Letters Patent of the UnitedStates, is:

1. An improved apparatus for conditioning tobacco and having a coolingwater supply, said apparatus comprising: a hermetically scalableconditioning chamber having means for insertion and removal of saidtobacco; a first steam ejector having a low pressure side and adischarge side, the low pressure side of said ejector being incommunication with the conditioning chamber; a condenser connected tothe discharge side of said first steam ejector, said condenser beingconnected through flow control means to the cooling water supply; asecond steam ejector having a low pressure side and a discharge side,the low pressure side being in communication with said condenser;transducer means responsive to the pressure condition in the condenserand operatively connected to control means to control the flow ofcooling water to said condenser and thereby to control the pressurecondition within the condenser to a predetermined level above the deadend level of the second steam ejector; and means for introducing steamto the conditioning chamber.

2. An improved apparatus for conditioning tobacco and having a coolingwater supply, said apparatus comprising: a hermetically scalableconditioning chamber having means for insertion and removal of saidtobacco; a first steam ejector having a low pressure side and adischarge side, the low pressure side of said ejector being incommunication with the conditioning chamber; a condenser connected tothe discharge side of said first steam ejector, the cooling water supplybeing connected to said condenser through flow control means; a secondsteam ejector having a low pressure side and a discharge side, the lowpressure side being in communication with said condenser; transducermeans responsive to the condition of the vapor in the interior of thecondenser and operatively connected to the flow control means to controlthe flow of cooling water from the cooling water supply to saidcondenser thereby being effective to control the vapor condition withinthe condenser to a predetermined level; and means for introducing steamto the conditioning chamber.

3. An improved apparatus for conditioning tobacco and having a coolingwater supply, said apparatus comprising: a hermetically scalableconditioning chamber having means for insertion and removal of saidtobacco; a first steam ejector having a low pressure side and adischarge side, the low pressure side of said ejector being incommunication with the conditioning chamber; a condenser connected tothe discharge side of said first steam ejector, said condenser beingconnected to the cooling water supply; an automatic control valveinterposed in the fluid connection between the cooling water supply andcondenser to control the rate of flow of cooling water to the condenser;

a second steam ejector having a low pressure side and a discharge side,the low pressure side being in communication with said condenser;transducer means responsive to the pressure condition in the condenserand operatively connected to the control valveto position said valve fordelivery of a measured amount of coo-ling water to the condenser tocontrol the pressure condition in the condenser to a predetermined levelabove the dead end level of the second steam ejector; and means forintroducing steam to the conditioning chamber.

4. An improved apparatus for conditioning tobacco and having a coolingwater supply, said apparatus comprising: a hermetically sealableconditioning chamber having means for insertion and removal of saidtobacco; a first steam ejector having a low pressure side and adischarge side, the low pressure side of said ejector being incommunication with the conditioning chamber; a condenser connected tothe discharge side of said first steam ejector, the cooling Water supplybeing connected to said condenser through flow control means; a secondsteam ejector having a low pressure side and a discharge side, the lowpressure side being in communication with said condenser; thermallyresponsive means operatively connected to the interior of the condenserand to the floW control means and eifective to position the flow controlmeans to control the flow of cooling water from the cooling water supplyto said condenser and thereby to control the temperature within thecondenser to a predetermined level; and means for introducing steam tothe conditioning chamber through the condenser and first ejector.

5. An improved process for conditioning tobacco by moistening it withsteam in a system including a conditioning chamber, a condenser, coolingwater supply for said condenser, a steam ejector to evacuate the chamberand discharging into the condenser, and an evacuator for the condenser,said process comprising the steps of: evacuating said condenser to apredetermined pressure level; introducing steam to said steam ejector toevacuate the chamber while continuing evacuation of said condenser withsaid condenser evacuator; introducing cooling water to the condenser andautomatically controlling the rate of introduction of the cooling waterin response to the transient vapor condition within said condenser;ceasing evacuation of the chamber and condenser when said chamber andcondenser are at predetermined pressure levels, respectively, andisolating the cooling water supply from the condenser when said pressurelevels are reached; and, passing super-heated steam into the condenserwhereby said super-heated steam is conditioned prior to introduction tothe conditioning chamber by cooling in passage through the condenser andsteam ejector to the conditioning chamber to a safe level forconditioning of the tobacco and to place the steam in the saturatedvapor state.

6. An improved process for conditioning tobacco by moistening it withsteam in a system including a conditioning chamber, a condenser, coolingwater supply for said condenser, a steam evacuator to evacuate theconditioning chamber and an evacuator for the condenser, said processcomprising the steps of: introducing steam to said steam evacuator toevacuate the chamber while evacuating said condenser with said condenserevacuator to predetermined pressure levels, respectively; introducingcooling water to the condenser and controlling the rate of intro ductionof cooling water in response to and as a function of the transient vaporcondition in the condenser to control the vapor condition within saidcondenser; isolating the chamber and condenser evacuators from thesystem when said chamber and condenser are at a predetermined pressurelevel and isolating the cooling water supply from the condenser whensaid pressure levels are reached; and, passing super-heated steam intothe condenser whereby said super-heated steam is conditioned prior tointroduction to the conditioning chamber by cooling in passage throughthe condenser to the conditioning chamber to a safe level forconditioning of the tobacco and to place the steam in the saturatedvapor state.

7. An improved process for conditioning tobacco by moistening with steamin a system including a conditioning chamber, a condenser, cooling watersupply for said condenser, and an evacuator for the chamber andcondenser, respectively, said process comprising the steps of:simultaneously evacuating the chamber and condenser to predeterminedpressure levels, respectively; introducing cooling water to thecondenser and automatically controlling the rate of introduction of thecooling water in response to and as a function of the transient vaporcondition in the condenser to control the vapor condition within saidcondenser; isolating the chamber and condenser evacuators from thesystem when said chamber and condenser are at a predetermined pressurelevel, respectively, and isolating the cooling water supply from thecondenser when said pressure levels are reached; and, passingsuper-heated steam into the condenser whereby said super-heated steam isconditioned prior to introduction thereof to the conditioning chamber bycooling in passage through the condenser to the conditioning chamber toa safe level for conditioning of the tobacco and to place the steam inthe saturated vapor state.

References Cited by the Examiner UNITED STATES PATENTS 2,217,935 10/1940Smith et al 131-140 2,245,833 6/1941 Smith et a1 131-133 2,285,3316/1942 Doyle 131133 2,285,469 6/ 1942 Smith et al. 131-140 2,528,47610/1950 Roos et a1.

2,621,492 12/1952 Beardsley et al 131133 2,832,353 4/1958 Doyle 131-1332,997,046 8/1961 Doyle 131-433 3,124,142 3/1964 Philbrick et al. 131133SAMUEL KOREN, Primary Examiner.

P, DEELEY, Assistant Examiner.

1. AN IMPROVED APPARATUS FOR CONDITIONING TOBACCO AND HAVING A COOLINGWATER SUPPLY, SAID APPARATUS COMPRISING: A HERMETICALLY SEALABLECONDITIONING CHAMBER HAVING MEANS FOR INSERTION AND REMOVAL OF SAIDTOBACCO; A FIRST STEAM EJECTOR HAVING A LOW PRESSURE SIDE AND ADISCHARGE SIDE, THE LOW PRESSURE SIDE OF SAID EJECTOR BEING INCOMMUNICATION WITH THE CONTDITIONING CHAMBER, A CONDENSER CONNECTED TOTHE DISCHARGE OF SAID FIRST STEAM EJECTOR, SAID CONDENSER BEINGCONNECTED THROUGH FLOW CONTROL MEANS TO THE COOLING WATER SUPPLY; ASECOND STEAM EJECTOR HAVING A LOW PRESSURE SIDE AND A DISCHARGE SIDE,THE LOW PESSURE SIDE BEING IN COMMUNICATION WITH SAID CONDENSER;TRANSDUCER MEANS RESPONSIVE TO THE PRESSURE CONDITION IN THE CONDENSERAND OPERATIVELY CONNECTED TO CONTROL MEANS TO CONTROL THE FLOW OFCOOLING WATER TO SAID CONDENSER AND THEREY TO CONTROL THE PRESSURECONDITION WITHIN THE CONDENSER TO A PREDETERMINED LEVEL ABOVE THE DEADEND LEVEL